EPA Permit Requires PREPA to Build New Pipe at South Coast Plant

Oct 22, 2008

The U.S. Environmental Protection Agency is proposing to renew a National Pollutant Discharge Elimination System permit, which would allow the Puerto Rico Electric Power Authority (PREPA) to discharge cooling water from its South Coast power plant into Guayanilla Bay, according to an Oct. 15 press release.

The permit requires PREPA to build a longer pipe to move the discharge of the warm, cooling water into a deeper and cooler part of the bay, so it will not adversely impact marine life.

"Constructing a new outfall pipe will provide a long-term solution that will protect aquatic life and the surrounding ecosystem," said Alan J. Steinberg, EPA regional administrator. "We have carefully considered the alternatives and met with the Guayanilla community several times during the decision-making process for this permit. We now invite further public review and input."

At the South Coast plant, an average of 870 million gallons per day of cooling water and trace amounts of treated wastewater and stormwater are discharged through an open canal into a small cove and then into Guayanilla Bay. The temperature of the discharge exceeds Puerto Rico's water quality standards.

EPA is proposing to renew the required permit, allowing PREPA to continue discharging, but PREPA must construct an outfall discharge pipe offshore so that the warm water can mix with the ocean's colder water in order to meet the water quality standard for temperature (90° F, 32.2° C). This new outfall pipe will replace the discharge canal that currently empties into the cove at the shoreline.

Multiple locations for the proposed pipeline are being considered. PREPA must go through an environmental review process and assess the impacts of building the pipe in various locations. EPA is also requiring PREPA to submit progress reports every six months, and the permit contains a compliance schedule with several interim milestones that must be met during the period leading up to construction of the new discharge pipe. PREPA will also develop a construction mitigation plan to minimize environmental impacts during the construction of the new pipe; the plan will include requirements for PREPA to transplant sea grasses and grow new coral in other locations.

The water discharge permit also requires that the location, design, construction, and capacity of cooling water intake structures reflect the best technology available to protect aquatic organisms from being killed or injured by being pinned against screens or other parts of the intake structure. Additionally, it sets requirements to prevent aquatic life from being drawn into cooling water systems and subjected to thermal, physical or chemical stresses.

The public comment period for this proposed permit runs until Nov. 30. Written comments will be addressed in EPA's final permit decision. Additional opportunities for community input will occur during the project's environmental review process. The draft permit and accompanying fact sheet will be available in the Guayanilla Public Library.

For more details, visit http://www.epa.gov/Region2/cepd/prlink.htm. For a Google Earth aerial view of the South Coast power plant, go to http://epa.gov/region2/kml/prepa_south_coast_power_plant.kml. (You must have Google Earth installed on your computer to view the map. To download Google Earth, visit http://earth.google.com/download-earth.html).